1. Field of Invention
This invention generally relates to providing a practical means for washing and disinfecting edible sprouts concurrently with propagation for producing sprouts free of dangerous pathogens, specifically to transform the rotary sprouting-type machine into an effective washing machine that can repeatedly, persistently, and automatically wash and disinfect seed and subsequent sprouts while providing key functionalities that improve overall sprout quality, increase shelf life, and help make rot-prone “bad” seed produce consistently good sprouts.
2. Prior Art
Dilemma Facing the Sprouting Industry:
Sprouts such as alfalfa, broccoli, radish, clover, onion, and various bean sprouts are often eaten raw. They are generally considered to be highly nutritious and many find them to be satisfyingly tasty. However, over the past 15 years there have been multiple outbreaks of foodborne illnesses associated with the consumption of sprouts affecting thousands of people worldwide. These outbreaks have been so numerous and subsequently publicized that in recent years sales of alfalfa and similar sprouts have dropped significantly.
Since 1999, the Food and Drug Administration (FDA) has warned consumers against eating raw sprouts due to an inordinately high number of people contracting foodborne illnesses from eating raw sprouts. (Federal Register/vol. 64, No. 207/1999 Oct. 27). The foodborne pathogenic health risk associated with sprouts has been significant not only in the United States but also abroad. For example:
“Between January 1995 and May 1999, there were 11 reported outbreaks in the united States associated with sprouts from commercial growers, 9 of which were due to various salmonella serotypes and 2 to Escherichia coli 0157.” (Federal Register/vol 64, No. 207/1999 Oct. 27) In a 1996 outbreak, over 450 cases of infection occurred from eating salmonella-infected alfalfa sprouts resulting in one elderly person dying from sepsis. (Food safety Network Technical Report #16, 2000 July)
“During May through August 1996, approximately 10,000 cases of Escherichia coli 0157:H7 infection associated with at least 14 separate clusters were reported in Japan. Most cases occurred in school-age children” (Emerging Infections Diseases, Vol. 5 No. 3, May–June, published by the CDC.) White radish sprouts were implicated in this outbreak which goes on record as the world's largest reported outbreak of E-coli 0157:H7 infection ever reported. (Food Safety Network Technical Report #16, 2000 July)
In 2004 alone as of August, there has already been nine sprout-related product recalls in the United states as listed on the FDA'S website.
Following recent outbreaks of salmonella Bovisorbificans in Oregon and Washington, a Jun. 3, 2004, “FDA Statement” warned: “FDA is reiterating its previous alert about eating raw sprouts. Those persons who wish to reduce the risk of foodborne illness from sprouts are advised not to eat raw sprouts.”
Pathogen Propensity High:
“Raw sprouts present unique food safety problems because conditions under which they are produced—growing time, temperature, water activity, pH (a measure of acidity) and nutrients—are ideal for the rapid growth of bacteria. If pathogens are present on or in the seed, these conditions are likely to encourage proliferation.”(HHS News, 1999 October, published by U.S. Dept. of Human Health Services). “FDA believes that the seed is the source of contamination in most of the foodborne illness outbreaks associated with sprout consumption.” (“Note to Firms that Grow, Condition, Store, or Distribute seed for Sprouting and to Firms that Produce, Pack, or Ship Fresh sprouts,” Terry C. Troxell, Ph.D., FDA, 2004 Aug. 19) “Microbiological analyses have shown that alfalfa seeds routinely contained high levels of microbial flora, including coliforms and fecal coliforms. Of even greater public health significance however, is the fact that pathogens can exceed 107 per gram of sprouts without affecting the appearance of the product.” (Food safety Network Technical Report #16, 2000 July)
Unfortunately, sprouts have an inherent propensity toward proliferating pathogens as the following research results suggest: “Bacterial flora of sprouts were often two to ten logs higher than that observed in seeds. E Coli 0157:H7 inoculated onto alfalfa seeds was shown to reach 106 to 107 cfu/g within 48 hours after the sprouting process began. Additionally, low levels of Salmonella species seeded into alfalfa seeds have been shown to increase by as much as four to five log in germinating sprouts. Therefore, the contamination of seeds with a few pathogens can potentially be amplified by the sprouting process and become a microbiological hazard.” (“Risks Associated with the consumption of Fresh Sprouts,” sylvanus Thompsons and D. A. Powell, Food Safety Network Technical Report #16, 2000 July)
So what is it with the prior art that, as mentioned above, such hazardous pathogens are “amplified” by? The article above goes on to explain: “These excellent conditions for bacterial growth are further facilitated by the fact that the sprouting process has no inherent kill steps that either prevent bacterial growth or eliminate them entirely.” (“Risks Associated with the consumption of Fresh Sprouts,” sylvanus Thompsons and D. A. Powell, Food safety Network Technical Report #16, 2000 July) The “sprouting process” must mentioned implicates the prior art prior-art equipment and methods used in the industry as being inept—even encouraging hazardous bacteria growth and proliferation. Consequently the industry is in serious trouble today, as noted above and herein.
My invention offers a practical means for eliminating such bacteria during and throughout the sprouting process by providing a virtual one-step procedure that is easy, requires less labor, is economical, yet is highly effective at killing the germs as the disclosure herein describes.
Pathogens that Have Been Implicated:
What are the foodborne offenders causing such an alarming health risk associated with eating raw sprouts? “There are several pathogens that have either been implicated in sprout-associated outbreaks or that have been identified as being a potential source of increased risk due to their ability to proliferate during sprouting. These include Salmonella, Enterohemorrhagic E coli, Bacillus cereus, Listeria monocytogenes, Yersinia entreocolitica and Shigella species. However, only Salmonella and Enterohemorrhagic E coli 0157:H7 have consistently been linked with sprout-associated outbreaks.” (“Risks Associated with the Consumption of Fresh sprouts,” sylvanus Thompsons and D. A. Powell, Food safety Network Technical Report #16, 2000 July)
Prior Art—How Sprouting is Done Commercially:
Alfalfa, broccoli, radish, clover, onion, and similar sprouts are all sprouted in very similar ways and generally take 3–6 days from seed to finished product. The time needed for producing the finished product depends on the seed-type as well as the water and ambient temperatures. Clean water and good seed are the only ingredients—no soil, no nutrient-fortified water as is the case with hydroponics.
To begin a sprout crop with the prior art, the seed is first washed—usually in a strong chlorine solution followed by a clean-water rinse. Next, the washed seed is loaded into a “rotary sprouter” machine, also sometimes referred to as a “rotary drum.” Such machines are very common. Virtually every grower in the business of producing alfalfa sprouts uses rotary sprouter machines. These machines slowly rotate growing chambers or “quadrants” around a horizontal axis and keep the seed and subsequent sprouts moist with intermittent sprays of water.
The rotary sprouter machine is used for growing sprouts either to full maturity or to half-term depending on the look desired. Rotary sprouters grow sprouts in bulk masses causing the sprouts to take on a “bulk” look. Such sprouts are good for packaging in bags. On the other hand, sprouts that are transplanted to trays or cups tend to grow straight up thus taking on a “turf” look. Neither method produces really safe sprouts. The saying “the proof is in the pudding” applies also in the case of sprouts. This is substantiated by the numerous outbreaks of foodborne illnesses related to eating raw sprouts, the numerous recalls, and the legitimate concerns and warnings of government health agencies. Taken all together these failures testify to one fact: The prior art does not and cannot produce safe sprouts. Additionally, outbreaks and recalls are occurring even among conscientious sprout growers who have sought to incorporate the best that the sprout equipment industry and scientific community can offer them—but it is clearly not enough! Sprouts produced commercially or otherwise in the prior art poses a serious health risk because the prior art can offer no practical, workable solution. Again, my invention provides such a needed practical, workable, and effective solution.
Prior Art—The Rotary Sprouting Machine—Part of the Problem:
Rotary sprouting machines, as mentioned, are used by virtually every sprout business who commercially produces alfalfa, radish, broccoli, clover, onion, or similar sprouts. While these prior-art machines grow the sprouts, they do nothing toward disinfecting the product. Actually, they are part of the problem. Such machines merely maintain a wet damp environment that is conducive to growing both sprouts and, unfortunately, bacteria. It should be made clear, at this point, that such machines do not offer means for washing the sprouts nor a means for eliminating pathogens. Even if a disinfectant is injected into their spray water, the pathogen problem is far too set into the product for such superficial attempts to be effective.
Sprouts such as alfalfa and the like are tender and can survive only limited concentrations of disinfectant exposure. Furthermore, spray applications of such low levels of disinfectant solutions accordingly dictated are highly ineffective. Why is this so? While a limited number of bacteria may be eliminated by any such efforts, large numbers invariably survive and continue to thrive. Such pathogens can become highly resistant and even more difficult to kill as hours go by. Not only does the sprout mass provide an ideal environment for bacteria to grow, but there is also an abundance of building blocks of proteins and other nutrients in which bacteria can coat, burrow, and fortify themselves with. Certain foodborne pathogens encase themselves in their own protective biospheres which must be stripped away or penetrated in order to reach the bacteria burrowed inside. The longer such pathogens are permitted to perfect their biospheres, the harder they are to kill. Such germs can be killed but to do it effectively it takes more than what the prior art can offer. This is especially the case considering the very limited concentration of disinfectant solution that sprouts can tolerate and survive. Even various surfactants have proven ineffective oxidizer complements. Furthermore, it is important to note that oxidizers cannot kill what they cannot contact intimately.
For non-biosphere bacteria, the proteins and organic matter surrounding them make them more difficult to wet with disinfectant. Also, the oxidizing power of any oxidant disinfectant is expended on the competing organic content of the sprout mass. These factors taken together make for a challenging problem—again, one that the prior art cannot meet. The prior art cannot offer a practical means for providing the aggressive and intimate wetting contact necessary to kill offending pathogens with the low concentrations of oxidizers such that the sprouts could survive. What is needed is persistent and repeated washings with low levels of disinfectant and with aggressive intimate contact of the disinfectant that is concurrent, frequent, and ongoing with the sprouting process. The prior art has no practical means for accomplishing such inclusions. Therefore, for these reason and any number of additional reasons, all efforts or methods devisable within the prior art have not, will not, and cannot solve the health-risks problems facing the sprouting industry today. My invention, however, offers a simple and practical means for effectively addressing all such issues as the disclosure herein will reveal.
Prior Art—Rotary Sprouter Further Explained:
The “rotary sprouter” or “rotary drum” commonly consist of a cluster of four horizontal sprout chambers or quadrants mounted together on a horizontal axle. Each quadrant or growing chamber has an open front where a door is mounted for containing the seed and sprouts. The quadrants or chambers slope to the front toward the doors where the water can drain out around the doors. Adequate drainage is important to prevent water logging and subsequent deterioration of the sprouts.
Prior Art—Unsanitary Screens in Ventilation Ports:
Rotary sprouters generally have a fan mounted on a stationary plenum that feeds air into the rotary drum's growing chambers. The fan introduces and circulates fresh air in and through the growing chamber. Accordingly, the back side of the quads has air openings as does the doors in the front for the flow-through ventilation. A weakness in this prior art, however, is that screens are installed in these openings to prevent loss of seed and sprouts. These screens are unsanitary because the mesh openings are difficult to clean and sterilize without removing from the machine. Pathogen-infected screens can contaminate subsequent crops thus contributing to the health risk associated with sprouts. A feature within my invention provides a means for retaining the product without any need for such screens thus enhancing sanitation.
Prior Art—Conclusions Regarding Rotary Sprouters
Considering the foregoing, clearly the prior-art rotary sprouter shares blame for the ineptness of the industry at producing sprouts that are free of borne-illness pathogens. Again, my invention, provides key enhancements and changes that transform the rotary sprouter machine into a sprout washing machine that can propagate, wash, and disinfect the sprouts perpetually all in virtually one simple step.
Prior Art—Other Offerings
What about other efforts in the prior art that are aimed specifically toward eliminating the pathogen problems facing the industry? Do any such discoveries or offerings provide a satisfactory solution? The follow information addresses these questions:
Prior Art—Use of Gamma Radiation:
“Research carried out by the U.S. Department of Agriculture concluded that treating alfalfa seeds and sprouts with a combination of chlorine and irradiation effectively safeguards them against contamination by E coli 0157:H7 and Salmonella. The report [from U.S. Department of Agriculture] further stated that the doses used to eliminate those organisms did not affect germination of seeds. However, the required irradiation dose is higher than the 1.0 kilogray dose allowed for fruits and vegetables. Further studies are required to confirm these preliminary reports.” (“Risks Associated with the consumption of Fresh Sprouts,” Sylvanus Thompsons and D. A. Powell, Food Safety Network Technical Report #16, 2000 July) Thus, currently treating “bad” seed and sprouts using gamma radiation is very unappealing. Furthermore, the level of public acceptance of irradiating a product that has traditionally bore a rather earthy organic health-food appeal is yet to be seen.
Prior Art—Heat Treatment of Seed “Limited Appeal”:
U.S. Pat. No. 6,415,547 B1 to Katsuyoshi Enomoto 2002 Jul. 9 describes a method for sterilizing seed using heat. “Application of heat to kill pathogens on alfalfa seeds has been investigated in a study that found treatment at 57 or 60 degrees C for 5 minutes appeared to be effective in killing S stanley without substantially decreasing germability of seeds. However, heat treatment has limited appeal because there is such a fine threshold at which bacteria can be killed and germination not destroyed.” (“Risks Associated with the Consumption of Fresh sprouts,” sylvanus Thompsons and D. A. Powell, Food safety Network Technical Report #16, 2000 July)
Prior Art—Chemical Treatment:
According an article in Food safety Network Technical Report #16, there are several studies done on the effectiveness of chemical treatment in eliminating pathogens on seeds for sprout production, including calcium hypochlorite, sodium hypochlorite, hydrogen peroxide, ethanol, and ozone. The effectiveness of any sort of a mere seed wash is greatly limited due to micro-cracks and crevices on and in the seed. The article says that no matter how lethal the treatment solution is, if the solution cannot reach the pathogens in the seeds, it cannot disinfect the seeds effectively. Therefore, even if there is any substantial reduction of the pathogens in the “bad” seeds, none of the chemical treatments can completely eliminate harmful organisms reside in the seeds. Referring to efforts toward disinfecting the seed the same article goes on to say, “Even if only a few organisms survive a seed treatment, they can grow to high levels during sprouting and contaminate the entire batch. Therefore, disinfection alone cannot be relied upon to ensure the safety of sprouts. The best results were obtained with the use of calcium hypochlorite; thus approval was granted for its use at 20,000 ppm.” (“Risks Associated with the Consumption of Fresh Sprouts,” sylvanus Thompsons and D. A. Powell, Food safety Network Technical Report #16, 2000 July)
Prior Art—FDA Guidelines:
“Despite the efforts by industry, government agencies, and academia to make sprouts safer, outbreaks continued to occur. It was therefore obvious that approved treatments, such as the routine use of seed disinfection treatment with 20,000 ppm of calcium hypochlorite, could not guarantee a safe product. This resulted in the FDA issuing new guidelines for the sprouting industry in October 1999.” (“Risks Associated with the Consumption of Fresh Sprouts,” sylvanus Thompsons and D. A. Powell, Food Safety Network Technical Report #16, 2000 July)
“The sprout guidance identifies a number of areas, from the farm to the sprouting facility, where FDA believes immediate steps should be taken to reduce the risk of sprout-associated foodborne illness. Specific recommendations in the guide include: development and implementation of Good Agricultural Practices and Good Manufacturing Practices in production and handling of seeds and sprouts; seed disinfection treatment; microbial testing before the product enters the food supply; and provision for trace-back. The guide recommends that seed should be subjected to one or more treatments that have been approved for reduction of pathogens on seeds and sprouts. This is to be followed by microbial testing of the spent irrigation water form each production lot to ensure that nay contaminated batch is not distributed. Test results before shipping products. The second document outlines the detailed procedures to be followed in implementing the testing.” (“Risks Associated with the Consumption of Fresh Sprouts,” Sylvanus Thompsons and D. A. Powell, Food safety Network Technical Report #16, 2000 July)
Still, it only stands to reason in the light scientific scrutiny and evidence that the FDA guidelines for disinfecting seeds and sprouts are not effective and will not be effective at getting rid of the foodborne illness problem associated with raw sprouts.
Prior Art—Ineptness Casting a Dismal Outlook:
“A great deal of effort has been spent by the research community trying to come up with ways to reduce the contamination in seeds. Despite these efforts, none of the intervention strategies developed to date are effective in achieving a complete elimination of pathogens in seeds or preventing re-growth of pathogens during sprouting. (“conclusions,” Sprouter's Journal, ISGA, Summer 2001, vol. 12, no. 1, p. 8)
To the people in the sprouting industry who make their living selling sprouts, the following speculative “solution” is a scary one indeed: “In the future, it might be useful to explore other strategies such a mandatory warning labels on individual packages offered for sale at retail outlets.” (“Risks Associated with the Consumption of Fresh Sprouts,” sylvanus Thompsons and D. A. Powell, Food safety Network Technical Report #16, 2000 July)
Little wonder, therefore, that a state of desperation for a solution to this plaguing problem is permeating the sprouting industry as is reflected in the following excerpt from a “Letter to ISGA Members” August 2004: “The International Sprout Growers Association (ISGA), and its Technical Review Board (TRB), are committed to addressing and eliminating the safety problems which have plagued the sprout industry. Its is necessary to work as quickly and effectively as possible to this end, and this will require the greatest level of cooperation and trust within the sprouting industry, and in both directions between the industry and the regulatory community.” (“Letter to ISGA Members,” Bob Sanderson, President of ISGA, 2004 August)
Again, my invention provides key and practical enhancements that change and transform the rotary sprouter machine from a germ paradise into becoming an effective disinfecting washing machine. The potential of my invention for offering a simple, practical solution to the problem is unsurpassed by any solution ever before offered. Furthermore, my invention offers additional benefits to the health of the sprout itself which encourages extended shelf life, market appeal, and value of the sprouted products.